Electro-mechanical wheel balancers are well known in the vehicle maintenance trade. These machines often include a chassis in the form of a cabinet in which various components and systems are housed. An imbalanced wheel is mounted to a rotatable shaft that extends from the chassis, typically using various mounting cones or other adapters. The shaft is rotatably driven by a suitable drive system (such as a direct drive motor or motor with a belt drive connected to a spindle) to create a dynamic imbalance condition. In addition, prior art balancing systems include an arm that can assist in measuring the wheel's dimensions (i.e., the distance from the machine and the wheels diameter). These devices have further included sensors to detect the wheel imbalance forces and electronic circuitry to analyze the forces and display an amount of weight needed to balance the wheel.
It is well known in the art to attach corrective weights (typically clip weights) of various masses to the outer and inner flange of a wheel to balance the wheel. After spinning the wheel to determine its dynamic imbalance, if any, the wheel balancer may resolve the imbalance vector into two opposite vectors corresponding to the positions on the two wheel flanges (outer and inner) where the weights are to be placed.
When using this type of balancer, the wheel balancer defines the locations where the corrective weights can be applied. An operator of the wheel balancer can then rotate the wheel to the location determined by the wheel balancer. Next, the operator places a corrective weight at top dead-center on the flange of the wheel in an amount calculated by the wheel balancer.
A challenge in placing weights on the outer surface of the wheel is accurately placing the weight at the location prescribed by the machine. If the weight is mislocated, then the wheel will show an imbalance when a check spin is performed. Determining the exact location of the top dead-center of the wheel where the balancing weight should be attached is complicated and time consuming. Thus, correctly placing the balancing weight on the first attempt can help reduce time and cost.
Many attempts to solve the above-mentioned problems have been made. For example, complex wheel balancers with laser-assisted weight placement systems have been developed. Such systems are disclosed, for example, in U.S. Pat. Nos. 6,484,574 and 6,244,108, and U.S. Patent Application Publication No. 2007/0175275. However, these systems are prohibitively expensive and their laser system is proprietary, non-portable, and unusable on many existing wheel balancers.
Accordingly, a need exists in the industry for a portable laser guide for a wheel balancer that can be connected to most existing wheel balancers and can indicate the top dead-center of a wheel so that the operator of the wheel balancer can accurately position and secure the balancing weight on the proper area of the wheel, thereby saving time and providing a more accurate balance.